FAQs About PFA

Thanks to semiconductor technology, the transistor size has gone from 10m to 7nm, even 5nm, and the purity of chemicals is astronomical. Semiconductor producers pay careful attention to any skewed results due to contamination during manufacturing (traces of metals, organic matter, and particles). Parts fabricated with fluoropolymers of high purity allow semiconductor companies to keep cost low to develop cutting edge chips. Typical applications of PFA in key areas of semiconductor manufacturing include:

Transportation and Storage

PFA ensures the high purity of electronic chemicals during the manufacturing process, avoiding contamination of electronic chemicals due to dissolution and erosion of reaction containers, thereby reducing the defect rate of wafers.

Chemical Distribution System (BCD)

BCD is a system that can accurately distribute chemicals. This system usually includes fully automatic instruments for mixing and diluting chemicals. PFA is widely used in BCD infrastructure, including making ventilation pipes, valves, sinks, etc.

Wet Etching and Cleaning

In this process, PFA is made into various tools, such as flow meters, to ensure the high purity of etching liquid and cleaning liquid; and PFA is not easy to crack during use, thus ensuring the high efficiency of production.

Chemical Mechanical Polishing (CMP)

The liquid used in the CMP process is a grinding liquid containing fine particles. If the particles in the grinding liquid are too large, they will leave marks on the surface of the wafer, resulting in defects in the product. The filter made of PFA prevents impurities in the grinding liquid from contacting the wafer to a certain extent.

PFA vs. PTFE: Correcting Common Misunderstandings

• The biggest difference between them is that PFA can be melt processed, while PTFE cannot.
• PFA material has excellent stress cracking resistance and better permeation resistance than PTFE. Although PTFE has a more perfect molecular gap, PFA raw materials form a denser structure after melting.
• Which one is better, PFA or PTFE, in terms of bending life (i.e. the ability to withstand repeated folding)? It is impossible to determine! It depends on your specific product structure, bending radius, temperature environment, material selection and application.
• PFA can maintain strong mechanical strength and burst pressure at relatively high temperatures. However, in actual use, PFA's temperature resistance is not as good as PTFE. PTFE is superior in terms of lower water absorption and weather resistance.
• The dielectric constant of PFA is the same as that of PTFE, and the dissipation coefficient is very similar, but the dielectric strength of PFA is much stronger than that of PTFE. The dielectric strength of PFA is 3-4 times that of PTFE, and PFA is superior to PTFE in high-frequency (UHF/microwave) insulation.
• PFA can maintain strong mechanical strength and burst pressure at relatively high temperatures. However, in actual use, the temperature resistance of PFA is not as good as that of PTFE. PTFE is superior in terms of lower water absorption and weather resistance.

FAQs About PFA

Is PFA safe?

Yes, PFA is considered safe for use in a variety of applications. It is non-toxic, non-flammable, and does not release harmful substances.

PTFE and PFA, which one is more suitable for semiconductor industry applications?

The first fluoropolymer to hit the semiconductor space is PTFE, followed by PFA. While PTFE is currently more widely used than PFA in semiconductor manufacturing, in specific key areas, PFA is preferred to PTFE. It is difficult to say which one is more suitable for semiconductor applications because they are all indispensable. Howerver, we can offer some guidelines on what fluoropolymers to use for semiconductors from two sides of the issue.

PTFE parts are usually machined from compression-molded PTFE blanks and are used to process containers, accessories, connectors, transport containers and liquid transfer. PFA is more used in the semiconductor industry to manufacture pipes, valves, tees, containers, etc. In addition, some complex structural parts and products that cannot be machined using PTFE can also be manufactured using PFA by molding. For fluid handling applications, PFA components can be manufactured by non-contact welding, thus avoiding contamination of the original molded parts.

In terms of cost, PTFE generally has a lower initial cost, especially for small batches or simple shapes, because it does not require mold tools. For large-scale production or complex parts, PFA is more cost-effective due to its efficient manufacturing process. Initial tooling costs can be offset by lower unit production costs over time.